Signaling device



T. J. SCOFIELD SIGNALING DEVICE Jan. 20, 1931.

ATTQRNEYS Jan. 20, '1931;

T. J. SGOFIEL D SIGNALING DEVICE Filed Aug. 24, 1926 {Sheets-Sheet ATTORNEYS} Patented Jan. 20, 1931 UNITED STATES PATENT OFFICE.

THEODORE J. SGOFIELD, or JACKsoN, MICHIGAN, AssIGNoR TO THE sPARKs-WITHINC- TON COMPANY, or. JACKSON, MICHIGAN, A CORPORATION or OHIO SIGNALING DEVICE Application filed August 24,1926. Serial No. 131,212.

This invention relates to certain improvements in signaling devices, andmore particularly to signaling devices of the diaphragm type that are commonly used upon automo -6 biles, motor boats, and other-vehicles.

The main object of the invention is the production of a new and noveltype of signaling device combining magnetic and rotary electric motor operation;

l ther objects and advantages relate to the details of the structure and the method of adjusting and correlating the parts thereof, all as will more fully appear from the following description taken in connection with 15 the accompanying drawings, in which Figure 1 is alongitudinalsectional view of'asignaling device of this invention.

Figure 2 is a section on line 2-2, Figure 1. Figure 3 is a section on line 3-3, Figure 1. Figure 4 is a longitudinal section through a modified form of signaling device of this invention.

Figure 5 is a longitudinal sectional view illustrating the bearings for the armature shaft and the method of adjusting the same. Figure 6 is a sectional view through a modified form of adjustable bearing. Figure 7 is a section taken on line 77, Figure4.

Figures 8 and 9 are diagrammatic views of usable circuits.

The signaling device shown in Figures 1 to 3 comprises a projector 1, a front case section 2 and a rear case section 3, between which sections the marginal portion of a substantially circular metallic diaphragm 4 is clamped in any suitable manner, as by means of bolts 5- The rear case section 3 is formed with a central opening -8 lin this instance substantially concentric with a cylinder 6 of magnetic material, such as any suitable metal having a radially and outwardly extending flange 7 at its forward end and brackets 8 extending from the flange and secured to the casesection 3 in any suitable manner as by rivets or otherwise.

The magnetic coil 9 is wound about the cylinder 6 and within the angle formed 5 between the cylinder 6- and theflange 7-- and is connected in circuit forthe passage of current inany'suitable manner, such as one ofthose hereinafter described.

The diaphragm 4 carries an armature or core 10'- positioned within and con enr i trio with the cylinder '6 and for the purposeof adjusting the armature 10., itis provided with a reduced screw threaded portion 11 threaded through a collar 12= secured to the diaphragm at substantially its 7 central portion in any suitable and well known manner, such as that illustrated. The armature lO- is locked in any desired position of adjustment with respect to rotor -13 by means of nut 14 threaded upon the projecting portion '-11. 1

'In this particular illustration, the rotor 13 is mounted upon and rotates upon an axis at substantially right angles to the axis of the armature "-10 and is positioned at the rear of the case section +3 opposite the central opening 84 in the case section -3, which opening is preferably substantially concentric with the armature 10 The cylinder 6 in addition to forming a support for the coil 9 also relieves the tendency for the armature l0- to pull off center in case the armature is not absolutely in the center of thecoil 9 the armaturev 1O being positioned concentrically of the cylinder 6. The rotor 13 is in the form of a spider of a pluralityof radiating arms 14 separated by. radial recesses or cut-out por tions 15, and as the rotor is formed of magnetizable material, the arms +14- constitute portions exerting comparatlvely great magneticstress while the recessed portions 15 between the arms 14- constitute portions of little, if any magnetic stress, and it is by reason of this fact that the structure operates in the manner that will hereinafter'ap- The rotor 13- is mounted upon the upper end of the armature shaft -16-: of an ordinary electric motor 17 and the rotor -13- is mounted in such a manner upon the armature shaft 16 as to be freely rotatablewith respect to the shaft, but is driven thereby through the medium ofa flanged collar --18 pressed upon the armature'shaft this frequently happens.

16 at a point adjacent the rotor 13 and provided with a pair of spaced upwardly projecting pins 19 and 20 which rotate with the collar and the armature shaft 16. The rotor 13- is provided with a depending pin --21- which maybe secured in a recess in the rotor.

Coil spring 22- has one end connected to the flanged collar 18- and its opposite end connected to the pin 21 so as to normally maintain pin 2l in contact with pin 20-, in which position with the motor rotating in the direction indicated in Figure 3, the armature and its shaft are free to ro tate with respect to the rotor 13 until pin -19 comes in contact with pin 21. In other words, the spring-2%- holds the rotor -13 normally ahead of rotation of the armature shaft -16, thereby allowing the armature to always start when current is applied to the motor for the reason that it allows the armature to start its rotation before it has to pick up its maximum load. This is particularly advantageous in case the armature stopped in low torque position, and

The motor may be of any usual and well known construction and in this instance comprises a U-shape sheet metal case --23- having the forward end of its legs reduced, threaded and projected through a bracket 2 4 secured to the case section 3- in any suitable manner, and the ends of the U-shape case where they project through the bracket 24 are adapted to receive nuts 25 for rigidly securing the U-shape case to the bracket.

The upper end of the motor shaft'has a bearing in the bracket 2%- and the lower end of the motor shaft is provided with an adjustable end thrust bearing in the base of the U-shape case, as for instance by the use of a opp-shape screw -26-- and locking nut 2 When the motor 17 and the coil 9- are simultaneously energized, the coil 9 magnetizes the armature ''10. As the arms or solid portions of the rotor -'13 move past the armature 10- during rotation of the rotor, the magnetized armature 10 tends to draw the solid portions 14:- of the rotor toward itself but as the rotor can not move in that direction, the armature itself moves toward the arms or solidlportions 14 of the rotor pulling the diaphragm el along with it.; As one of the recesses -15 comes opposite the armature 10 there is little, if any, magnetic attraction between the armature 10 and the rotor and as a result the natural spring or resiliency of the diaphragm overcomes any existing magnetic attraction and the diaphragm swings away from the rotor -13. The next arm or solid portion 14lagain provides sufficient magnetic attraction between the armature and the rotor so that the armature again moves toward the rotor and at the next recess -15 the diaphragm again swings away and in this manner vibration of the diaphragm to produce sound is effected.

The diaphragm lhas a natural period of vibration of its own and in order to produce maximum sound must swing or vibrate at substantially this frequency, and to a con siderable extent the natural frequency ofthe diaphragm governs the speed of the motor -17 as the motor will adjust itself to a speed at which it can perform the required function with the least exertion and the motor will substantially synchronize its speed of rotation to conform with the natural frequency of the diaphragm.

1 In Figures 4, 5 and 6, and 7 the rotary motor is arranged with the axis of its armature shaft substantially perpendicular to the diaphragm and substantially parallel with the axis of the armature 10. In thiscase the armature 10 can be rigidly secured to the diaphragm as the necessaryrelative adjustment between the armature and the rotor 13 can be effected by mere endwise adjustment of the armature shaft. In this particular illustration, the rotor 13 is of slightly different form but involves in like manner as the rotor ofFigures 1, Qand 3, a series of radially projecting arms '14 separated by cut-out portions or radially recessed portions which produce little, if any,

magnetic stress in connection with armature 10. i

The bearings for the armature shaft illustrated more clearly in Figure 5 constitute in themselves a novel structure applicable to any form of signaling device or motor in which adjustment of the armature shaft is desirable, while operation may be carried on with a minimum of friction.

In this structure the armature shaft 16- has its forward bearing in a flanged sleeve '30 threaded into the rear case 3 and provided with a lock nut 31 for maintaining the sleeve in desired position.

In Figure 5 the flange -32 upon the rear end of the sleeve 30 is formed with a ball race adapted to receive anti-friction balls -33 and the shaft 16 is formed with a cone 34. adapted to bear againstthe balls 33. In this illustration, the cone 3l is secured to the shaft 16- and may, as shown, rest against the shoulder -35 formed on the shaft. The cone b&. is held in contact with the balls -33- by means of a spring 36 secured to the base of the U-shaped case -23 and extending across the rear end of the shaft 16- where it projects outwardly from its bearing in the case 23.

The rear end of shaft -16 is preferably rounded, as shown, for substantially'point contact with the spring bar 36. With this construction, it is possible to place considerable pressure upon the rear end of the shaft 16- holding the cone -3lfirmly against the balls 33 without retarding rotation of the armature. In Figure 6 a slightly modified form ofv adjustable bear- .ing is illustrated in that a thrust washer 38 is substituted for the balls -33- and bears against the rear end of the flange 32- and is held against the flange by means of a shoulder or disk 39 mounted on and secured to the shaft 16 at the rear of the thrust washer 38 and resting in like manner as cone 34 against shoulder 35- upon the shaft '16.

The operation of this structure in producing' diaphragm vibration is the same as the operation described in connection with Figures 1 to 3. As before stated, the coil 9 and motor 17 are simultaneously energized and in Figures 8 and 9 I have illustrated the coil and motor as'connected in series and parallel respectively with a source of potential as battery 40.

Altho I have shown and described specific structures as illustrative of embodiments of the invention, I do not desire to restrict myself to the details of form, construction or arrangement of the apparatus or the parts thereof, as various changes and modifications may be made in each and all of the same With- 7 out departing from the invention as set forth in the appended claims.

I claim: I

- 1. A signaling device comprising a diaphragm, a rear diaphragm case including an apertured rear wall, a magnetic tube carried by said case upon the side of the rear wall facing the diaphragm and aligned with the Wall aperture, an electro magnet mounted on said tube, a movable core secured to the dia phragm and positioned substantially concentrically within said tube, a rotor positioned externally of the rear diaphragm case wall and consisting of a plurality of arms separated by recesses and aligned with the removable core through the wall aperture, and means including an electric motor for rotating said rotor to bring the arms and recesses alternately opposite the core.

2. "A signaling device including a diaphragm, a rear diaphragm case including an apertured rear wall, a tubular electro-magnet carried by said case upon the side of the rear wall facing the diaphragm and alined with the wall aperture, a movable core secured to the diaphragm and positioned substantially concentrically within the tubular electromagnet, a member movable past the core and having radial arms spaced by intervening recesses exercising comparatively high and low magnetic stresses respectively upon the movable core, and an electric motor for operating the last named member.

3. A signaling device including a diaphragm, a rear diaphragm case including an apertured rear wall, a tubular electro-magnet carried by said case upon the side of the rear wall facing the diaphragm and alined with the wall aperture, a movable core secured to the diaphragm and positioned substantially concentrically within the tubular electromagnet, a rotary member movable past the core and having radial arms spaced by intervening recesses exercising comparatively high and low magnetic stresses respectively upon the movable core, and an electric motor for operating the last named member.

In witness whereof I have hereunto set'my handthis 31st day of July, 1926. I

THEODORE J. SCOFIELD. 

